Difference between revisions of "Big Data Lab notes 02/19/14"

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We will work with three tables. Here are the table definitions:
We will work with three tables. Here are the table definitions:


<code>
create table Sailors(
create table Sailors(
         sid int PRIMARY KEY,
         sid int PRIMARY KEY,
Line 43: Line 44:
         age int
         age int
         );
         );
</code>


<code>
create table Reserves(
create table Reserves(
         sid int,
         sid int,
Line 50: Line 53:
PRIMARY KEY (sid, bid, day)
PRIMARY KEY (sid, bid, day)
         );
         );
</code>


<code>
create table Boats(
create table Boats(
         bid int PRIMARY KEY,
         bid int PRIMARY KEY,
Line 56: Line 61:
color char(10)
color char(10)
         );
         );
 
</code>


You can download the sample file with these statements as well as some sample data from http://vgc.poly.edu/~juliana/courses/BigData2014/Lectures/Lab-SQL/sailors-mysql.sql
You can download the sample file with these statements as well as some sample data from http://vgc.poly.edu/~juliana/courses/BigData2014/Lectures/Lab-SQL/sailors-mysql.sql


== SQL Cheat Sheet ==
== SQL Cheat Sheet ==

Revision as of 13:46, 19 February 2014

Today, we will work on SQL queries.

Before the class, please download mySQL from from http://dev.mysql.com/downloads. There are many different versions, select MySQL Community Server.

Installing and starting mySQL

mySQL has an extensive documentation, including installation instructions for different OSes, for example, MacOS: https://dev.mysql.com/doc/refman/5.7/en/macosx-installation.html and for Windows: http://www.mysql.com/why-mysql/windows/

I run mySQL on MacOS, so here's what I did after I installed the system to 'start' the database: 

    shell> cd /usr/local/mysql
    shell> sudo ./bin/mysqld_safe
    (ENTER YOUR PASSWORD, IF NECESSARY)
    (PRESS CONTROL-Z)
    shell> bg
    (PRESS CONTROL-D OR ENTER "EXIT" TO EXIT THE SHELL)

You can also use the shortcut command: mysqlup

To connect to the MySQL server, on a terminal, invoke `/usr/local/mysql/bin/mysql.

You can add aliases to your shell's resource file to make it easier to access commonly used programs such as `mysql' and `mysqladmin' from the command line. I have added the following 2 lines to my .bashrc: 

    alias mysql=/usr/local/mysql/bin/mysql
    alias mysqladmin=/usr/local/mysql/bin/mysqladmin

You can also modified my PATH environment variable to include /usr/local/mysql/bin:

export PATH=$PATH:./:/usr/local/mysql/bin:/usr/local/mysql/bin:/usr/local/hadoop-1.2.1/bin:/usr/local/pig-0.12.0/bin

Our running example

We will work with three tables. Here are the table definitions:

create table Sailors( 

       sid int PRIMARY KEY,
       sname varchar(30),
       rating int,
       age int
       );

create table Reserves( 

       sid int,
       bid int,

day date, PRIMARY KEY (sid, bid, day) 

       );

create table Boats( 

       bid int PRIMARY KEY,

bname char(20), color char(10) 

       );

You can download the sample file with these statements as well as some sample data from http://vgc.poly.edu/~juliana/courses/BigData2014/Lectures/Lab-SQL/sailors-mysql.sql

SQL Cheat Sheet

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